Line tension signal



Jan. 5, 1954 A. F. RHODES ET AL LINE TENSION SIGNAL 4 Sheets-Sheet l Filed Jan. 8, 1951 ,/f mm @www MEN f, f/oofs WML/,4M 5. @ACH/MAN INVENTORS Tfo/Sfvf/ b Lim MQ Jan. 5, 1954 A. F. RHODES ET A1.

LINE TENSION SIGNAL 4 Sheets-Sheet 2 Filed Jan. 8, 1951 ww Nw I .lill QN @n wv n ww n@ m i J mm i I- l i ,W No I-: \|A. v Q\\ MQ\ Jan. 5, 1954 A. F. RHODES ET AL LINE TENSION SIGNAL 4 Sheets-Sheet 3 Filed Jan. 8, 1951 .NN mm1 Mf/v f /QHOQES M//LL/A/w 5, @A0/MAN INVENTORS T roe/var lBY Jan- 5, 1954 A. F. RHODES ET AL LINE TENSION SIGNAL 4 Sheets-Sheet 4 Fi led Jan. 8, 1951 KRW YMNN

MNNNN,

IN VEN TORS EMM -rTO//VEV @MRW www www. um? NS j N i mwN i w NN@ 1| I YNKN J Y vm KL Patented Jan. 5, 1954 LINETEN SION SIGNAL Allen F. Rhodes andWilliamS. Bachmau,

Houston, Tex.`

Application January, 1951, Serial N 0. 205,016

(Cl. 11G- 67)A 12 Claims. 1

This invention pertains to a device for giving a signal when the tension thereon exceeds a certain value and more particularly to such a device used to signal the increase over a predetermined adjustableamount of theY tension in a cable or line used to make up drillpipe, casing,`

or tubing employed in oil well` drilling andproduction, such tension corresponding tothe desired torqueon the screw threads-of the parts' being connected.

It is an object of the invention to providev such a device which will be inexpensive toconstruct, operate and maintain, and which will be simple, safe; and reliable 'in operation. i

It is another object of-the invention to provide such a device which will be bothv light in weight and yet extremely durable.

It'is a further object of thelrinvention to provide such a device whichwill 'give an audible as r well as visual signal when the line tension has.

exceeded an adjustable predeterminedrpoint.

It is another object of the invention to provide such a device which 'will automaticallyV reset, itself when the line tension has been reduced sufficiently below the predetermined point.

Other objects and advantages of the invention will become apparent as the disclosure thereof.,

proceeds.

For a detailed description of preferred embodiments of the invention reference will `now be tension signal embodying the invention;

f3() made'to the accompanying drawings wherein:

Figure 1 is an axial section .through aline Figure 2 is a viewv of the left end of ,the device shown in Figure 1;

Figure 3 is a view of the right end of the device shown in Figure 1;

Figure 4 is a transverse section on the line A 4-4 of'Figure 1;

Figure 5 is a transverse section on the line 5-5 of Figure y1;

Figure 6 is a transverse section on the line 6--6 of Figure l;

Figure 7 is a transverse section on the line 1 1 of Figure 1;

Figure 8 is a transverse section on the line Y 8-8 ofFigure 1;

Figure 9 is a transversesection'onv the line 9-9 of Figure-1;

Figures 10 and 11 are'isometricrviews of the.

lever and' some of theY associatedY elements of the device Vshown in Figure 1, showing the parts in different positions during Ythe` operationof the device; 'l

Figure 12- isa bottom plan view or a modified V 2 form of line tension indicator embodying the invention, with the housing partly broken away to expose the interior of the device;

Figure 13 is a side elevation, partly in section, Y `of the device shown in Figure 12;

Figure 14 is a left end View of the device shown in Figure 12 and Figure 15 is a transverse section taken on linev l5-I5 of Figure 13.

Referring to Figure 1, the line tension signal comprises a barrel 20 `of generally cylindrical form. vFor weight .reduction thek barrel is of reduced outer diameter at theright hand portion, the left hand portion being of larger outer diameter to provide Va heavier sectionwhere the load is greatest. This leaves a shoulder 2l therebe- .v

tween. The right' end of the. barrelis provided with 'a screw thread to which Vis connected a screw cap 22.' To the disc 23 forming the end of the screw cap there is welded a post 24. A U shaped strap or stirrup ,25' is pivotally connected to the post bya pin 26` secured by cotter pin 21;

The strap is of such size that the end ofa set of pipe tongs will iit' snugly vin the eye formed `between the strap and the end of the post.

Barrel 2G is provided with a plurality of grooves 29 running parallel to the axis of the barrel and spaced` apart about'the circumferenceof the barrel. A lock pin 301s screwed through a hole in the screw cap and held in place by a lockwasher 3|. The end of pin 30 does not bottom in the grooves 29'even when it is screwed in Vas faras it Will go, but the end of the pin does under such conditions extend into the groove far enough to prevent relative turning of the screw cap and barrel.

Within the' barrel is disposed a helical compression spring 40, one end of which bears against the screw cap on the right end of the barrel. A piston 4l is slidably disposed inside the barrel. The right end 42'of the piston is reduced to t' inside the left endof spring .40. (See Figure 9, in which the spring 40. is omitted for clarity.) The left end. of the .spring bears against the shoulder 43'of the piston formed at the juncture of the large and small diameter portions thereof.

A pair of bearing blocks 50, 5| (seealso Figure 8), each having one hat face and oneface curved to iit the inside of the barrel, are secured inside the vbarrel* with their flat faces parallel by means of a plurality of screws (not shown) passing through .the barrel. The sides of the piston 4l are cut ofi flatat the left end 52 yof the piston to fit between the bearing blocks. (See Figure 8.)

The center portion 53 of piston 4I is cylindrical and normally bears against the right hand ends 55 of the bearing blocks, being urged against them by the spring 40 which is in compression.

Between the bearing blocks is pivotally disposed a lever B having trunnions 6l and 62 (see also Figures 6 and 7) extending into bearings 63 and ell. The lever is centrally slotted at 65. The piston dl is centrally slotted at 66. A link el has one end pivotally secured to the lever in slot 65 by means of pin 58 and the other end pivotally secured to the piston in slot 66 by means of pin 69.

A piston lo has two iiat sides (see also Figures 4 and 5) sliding between the bearing blocks 5B, 5! and tivo curved sides conforming to the interior of the barrel. A disc 1I having an aperture 'i2 therethrough is welded to the end of the barrel. An O ring 'i3 oi neoprene or other oil resistant rubberlike material is disposed in an annular groove ill in the aperture l2. A post l5 on the piston extends through the O ring, sealing therewith. A chain shackle le is pivotally connected to the post by means of a, pin ll passing through the eyes i8, 'i9 thereof Y(see Figure 2) and an aperture Sil in the post and secured by Cotter pin 8l. An eye is thus formed between the body of the chain shackle and the end of the post within which may be secured a bight on the end of a cat line.

Four compression springs, including the two shown at 9U, 9|, in Figure 1, are disposed each with one end in one of the sockets 92, S3, ell, 95 (see Figure 4) in the piston lil, and with the other end in one of the four sockets in the disc 'ii including the socket 96 shown in Figure 1. These springs urge piston Hl to the right so that it normally bears against the flat face Si of lever GG which is normally held in a position with face @l perpendicular to the axis of the barrel, but in Figure 1, however, the piston is shown moved slightly to the left under tension applied to the device at the spring shackle 'i6 and strap 25. This much travel of the piston 1B represents lost inotion and does not change the position of lever Gil which is shownin its normal position.

A link Mit has its left end disposed in slot lill in the piston 'it and is pivotally connected thereto by means of pin H32. The right end of link it@ is disposed in slot |93 in the top of lever Eil. A pin Hill extends thro-ugh the right end of link ide and is adapted to engage in depressions iii in the side of the lever @ii (see also Figures 10 and 1l). A compression spring He (omitted from Figures l0 and 11) has its left end disposed in a recess itl in the piston nl and its right end secured to link lo@ by a screw $63 so as to urge link ide clockwise, as viewed in Figure 1, into slot w3, so that pin llll rests down behind the ends M39, H0 of the lever 69. If there were no tension at all on the device, the springs 9), 9E would move the piston to the right of the position shown in Figure l into contact with lever 50, and the pin itil would not be in the bottom of depressions m5, this overtravel being necessary in order to allow the device to reset in the manner subsequently described herein.

There is a hole H20 through piston 'iD to prevent air pressure on opposite sides thereof from damping its motion. The slot 66 goes clear through piston #il and thereby serves the same purpose. The interior of the device may be suitably lubricated with oil or grease.

in operation of the device just described, the initial load will move the parts to the position shown in Figure 1. Thereafter additional tension will be transmitted from stirr-up 2E through pin 2S, post 2t, cap 22, barrel 2Q, and bearing blocks 5S, 5l, to trunnions el and 62 of lever Si? and Vwill be transmitted from shackle i6 through pin il, post 75, piston lil, pin 92, link Il, pin IM, to the ends itl, [le of lever 59. A fraction of this tension force, depending on the relative lengths of the lever arms, will be transmitted by lever 653 through pin e3, link el, pin 59, and piston il to spring fiil, tending to coinpress the spring fill. When this force exceeds the initial compression of spring @il it will compress, lever te will turn (see Figure l0), and the shackle 'iii will move away from stirrup 25.

The stirrup, shackle, pins, posts, screw cap and barrel, pistons, lever, links, and spring le thus constitute a resilient connecting means. Spring @il constitutes an elastic means which is resistant to deformation with a force proportional to some function, usually approximately linear, of the deformation and the remainder of the resilient connection constitutes a means to impose a force thereon proportional to a function, usually linear, of the tension applied to the device. The lever Se serves as a means to reduce this force to less than the line tension. While spring i is a cornpression spring, by redisposition of the means to apply force thereto a tension or torsion spring could be substituted therefor. Also, instead of an elastic solid, an elastic fluid could be used for the spring sil.

Upon the application of additional tension to the device the lever Si) continues to turn counter clockwise, as viewed in Figure 1, until the ends me, i iii thereof slip under pin I (see Figure il). shackle le then is free to move to the left (except for the resistance of the four springs de, S i et al.) and moves away from stirrup 25 until piston lil engages disc il. Thereafter load is transferred from stirrup 25 through pin 2t, cap 22 and barrel 2li, to disc l, and from disc il thru piston lil, post l5, pin 'il to shackle le. Thus, the trip means or break joint constituted by link Eile and lever 86 serves to disconnect the resilient connecting means and the load is thereafter transferred to the lost motion joint or connection comprising the piston le, the barrel 2i), and disc il. This prevents complete separation of the parts connected by the device.

When the load is transferred from the resilient connection to the lost motion connection, by operation of the trip means, the energy stored in spring @lil is released and causes the spring to expand forcing piston d! against the bearing blocks and the impact produces a high intensity, loud, audible signal or noise. At nearly the same time the piston lil, released from spring lid, travels freely under the force of line tension (except for the compression of the four reset springs dil, Si, and others), closing the space between the piston and the disc 'H still remaining at the time the pin les slipped over the ends lili?, i it of lever 56. The piston iii strikes the disc 'ii producing a high intensity, loud, audible signal or noise.

Upon reduction of the line tension to less than the force exerted by tre reset springs, they will serve as part of means to reset the device by pushing piston "s0 'back against the fiat face 97 of lever @il which has already been returned to its initial position by the release of spring 48. As the piston l is returned to normal or starting position the pin Itis on link let rides up over the ends IGS, lill of lever B and is forced aac-asm The four resetsprings 90;.9|' fet'a1....and.springe.

le'iconstitute elastic means resistingY deformaf. tion with a .force proportional to :1a function,

usually V'nearlyglinean of their deformation or.;n compression. Byuitable .variationof the means f includingithe piston-10,-disc'1l, and link llllliforl imposing Aa `force thereon proportional to Va. funcA tionof the, line tension,` othery types. cip-springs; tension, AtorsionVor vfluidcould be'used `.instead of the compression springs shown.

By adjustingthepositicn of screw. cap '22:onbarrel fthe initial deformation -.or.f stress :ofspring 40 can be varied toy change the predetermined line-tension needed toproduce the predetermined defor-mation of the spring 40 required to release the trip means orbreak joint. The prestressing ofthespring 40 insures that a loud report will beproduced when the spring is ATreleased. The audible signal given by the hammering of piston 4| against the bearing blocks and of piston 1li against disc-1li is to be distin-4v guished from a mere indication such as the movement of a pointer over a scale which has to' be I read as in anordinary springibalance. In ad. dition to the audible signal a visual signal can also be produced, e. g., by painting the inner portion of post 15 a distinctive color which becomes exposed to the outside only during the extreme movement of the piston 10 after the break joint has tripped. The sudden appearance of the co1- ered part of the post is likewise a. distinct signal to be distinguished from a mere indication which has to be read.

The safety features of the invention include the complete enclosure of the Working parts by the outer barrel and the provision of a lost lmotion connection to take the load after the break joint has disconnected the resilient connection. Both of these points are very important to the workmen in the vicinity of the device when in use since failure of the internal structure cannot scatter metal parts through the air at high velocity, and release of the break joint does not free the cat line to allow it to fly loose.

By virtue of the means for reducing the force cn the signal actuating spring, which includes the lever 50, the spring need not be so large and heavy. At the same time the spring is large enough to produce a loud signal and stand the considerable abuse inherent in oil field use. The self-resetting feature insures the device will be used each time a connection is made, so that all connections will be made up tight enough to prevent leaks and yet not so tight as to overstress and gall the threads.

Referring now to Figures 10 through 13, the device there shown is generally similar to that previously described and most of the parts and operation thereof will be easily understood without further description. Similar parts have been given reference numbers two hundred greater than used for the first described embodiment. Differences from the previous construction include the bell 49|) secured to posts 242A, 242B on piston 24|, to produce an audible signal of longer duration than the reports occurring when the piston 26| strikes the bearing blocks 250, 25|, and piston 21|! strikes disc 21|. A further difference lies in the use of twin posts 215A and 215B connected to piston 210 and extending through apertures 212A and 212B in disc 21| and the provision of a pin 211 passing through the outerV 1 ends of?l the: posts" y.to Jprovide a .means Lto: 1.a

connect-.the devicesto. a cat` line' or. cable.: Whilepreferred. embodimentsof :.the'inventon have been shown andzdescribedit is obviougthatt; many. `modiiications -thereofxcan befzmadmbyv one.I y.. skilledazin. the. art -without departing fromzrthe.. c spirit of the invention; and` it .is desired to pro-i` forms of the invention?.

tect by Letters Patent all falling; `within the i scope:` of the following uclaims; We 'claims 1. In combination, means to connectone meme-v ber` to.- another to transmit tension therebetween including elastic signal actuating means resistant to deformation with a force proportional toqa L. `function `of the deformation, means toimpose; on:v the signal actuating. means fa forceproportional to -a function 'offthefline tension; the lastrsaid 1 means including'. trip 1 vmeans disconnecting; .the

force imposing means. upon` predetermined. vdes.v formation cf the signal actuating mea-ns, means; connected to the signal actuating mea-nsnto'pro `1 duce a signal whenrsaid trip means has .discone:vv

nected-said force imposing means, elastic reset;

meansrresisting. deformation with. a force -prozportional to a function of the deformation, meansf to apply to the reset means a force proportional .l

to a function of the line tension, and means connecting the reset means to the trip means to reconnect the force imposing means to the signal actuating means upon reduction of line tension, said connecting means continuing to function after the line tension has surpassed the point required to actuate said signal.

2. The combination of claim 1 in which the force imposing means is adjustable to vary the line tension required to produce said predetermined deformation of the Signal actuating means.

3. The combination of claim 1 in which the signal is audible and the signal actuating means is prestressed to increase the intensity of the signal.

4. In combination, Imeans to connect one member to another to transmit tension therebetween including a break joint held in connecting position by a spring subjected to a force varying with the line tension and breaking upon increase of line tension beyond a predetermined point and a lost motion joint paralleling the break joint and taking tension only after disconnection of the break joint, and the break joint taking no tension when disconnected.

5. The combination of claim 4 in which the spring of the break joint is released upon line tension exceeding said predetermined point and means is connected to the last said spring to produce an audible signal upon said release.

6. The combination of claim 4 in which a reset spring is connected to the relatively movable parts of the lost motion joint to urge them away from load taking position to reset the break joint on reduction of line tension.

7. The combination of claim 6 in which the force of the reset spring is small compared to the line tension required to disconnect the break joint, whereby movement of said lost motion joint to tension taking position upon disconnection of said break joint occurs rapidly producing an audible signal.

8. In combination, means to connect one member to another comprising a resilient connection, means to break said resilient connection upon imposition of tension exceeding a predetermined value and a lost motion connection paralleling the resilient connection adapted to take tension load only after the resilient connection has been produce a signal upon transfer of the load from the resilient connection to the lost motion connection, said signal being actuated by the energy stored in said resilient connection prio to said transfer.

l0. The combination of claim 9 with means to reconnect the resilient connection upon reduction of line tension.

11. In combination, a cylindrical barrel having a screw thread on one end, a screw cap screwed to said one end, a securing device connected to said screw cap, a compression spring disposed inside said barrel with one end bearing against said screw cap, a piston inside said barrel making a sliding fit therewith, said piston bearing against lthe other end of said spring, an abutment inside said barrel limiting the travel of said piston in the direction away from said screw cap, said spring being prestressed to urge said piston against said abutment and normally causing it to seat thereagainst, a lever pivotally mounted inside said barrel, a link connecting said lever to said piston a second piston slidably disposed in said barrel, a link pivotally connected to the second piston and releasably pivotally connected to the lever, an apertured disc closing the other end of the barrel, a post on the second piston extending through said aperture, another securing device connected to said post, a spring con nected to said second piston urging it away from said disc and a spring connected to said link urging said link into engagement with said lever.

12. In combination, means to connect one member to another member; trip means to break said connection upon increase of load on said connection beyond a predetermined value, and means to connect said members paralleling the first said means to take load after the connection of the iirst said means has been broken.

ALLEN F. RHODES. WILLAM S. BACHMAN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,379,874 Miller May 31, 1921 2,287,516 Endres June 23, 1942 2,414,161 Moore Jan. 14, 1947 

